Dear Marcello,
No idea what the issue is - and it seesm you are the only one who reported this so far.
I understand that you observe that sometimes ASE runs all 'DUMP DATABASE' jobs one after each other - despite the fact that you scheudled them to run weekly on each work day only (at 23:00 o'clk)
To get you my opinion on you question above:
>So to explain, the job that should run on Mondays is scheduled to run weekly at 23:00, with a starting date of >May 27th (a Monday) and no end date; it's not specified that the job should run on Mondays, though. So I >think this is why it run on a Sunday.
In my understanding jobs scheudled weekly with start date on a Monday (and no end date) should run always on a Monday and never on any other day , so I don't understand the behaviour.
Did you observe under which circumstances you observe the issue (e.g you indicate that the first time it was after a unplanned Windows Server outage?)
I suggest you capture the info according to SAP note
1835880 - SYB: How to diagnose issues with Sybase ASE Job Scheduler, ATM, or Scheduled Jobs
(so far don't enable the additional trace flags mentioned in the note)
If you can't figure the root cause from that information I suggest to open a new support case at SAP describing your observed behaviour.
HTH
Tilman